This invention relates to a device for holding flat or ribbon cable of the type having a plurality of individual round conductors in a predetermined aligned flat arrangement to facilitate proper termination thereof. The invention further relates to a termination system for cutting the cable after being pressed into position, and then pressing a connector onto the cable. In another aspect the invention relates to a method of aligning such cable in a flat position to facilitate proper termination, and further, to the method of cutting the cable and terminating the cable with a connector.
In the field of microelectronics, and other electronic areas such as in automobile computers, it has been increasingly common to use flat ribbon cable for the purpose of establishing interconnections between personal computers and their various peripheral devices. Flat ribbon cable typically is a cable made up of a plurality of individual round conductors which are each individually insulated, i.e., covered by an insulated sheath, and laid out in a generally flat configuration wherein each conductor is parallel to an adjacent conductor such as to make up a generally flat cable. Termination of such cable is generally made with a multiple socket or pin contact connector which is pressed onto the cable to establish connection. The connector typically includes a plurality of insulation displacement contacts, each one for a respective conductor of the cable such that when the connector is clamped shut onto the end of the cable, electrical connection is established between each of the conductors of the cable and their respective insulation displacement contact of the connector.
In the prior art manual means have typically been provided for aligning the individual conductors of the cable and clamping them down into a predetermined position. Thereafter, a separate tool was employed to clamp the connector onto the end of the cable. Although generally working satisfactorily, this was a time consuming process due to the relatively small size of the individual conductors and the necessity for having precise alignment to ensure that no short circuit results because of misalignment of the insulation displacement contacts of the connectors with respect to the covered conductors of the cable.
A further development in the prior art involved a modification to the discussed flat cable whereby slits were placed in the insulation between respective conductors of flat cable to permit twisting and compacting of the cable throughout its length into a generally round configuration. Such a round configuration was desirable because of its reduced size and in addition, the slit arrangement between conductors of the ribbon cable permits bending and twisting of the cable into any desired configuration, something that was not possible with conventional flat ribbon cable. To hold the cable in a round configuration, an outer insulative sheath was provided. This type of cable is available commercially, for example, from Amphenol Products as Spectra Strip.RTM. Round N' Flat.RTM. cable.
A result of providing the flat cable in a round configuration is that because it is maintained in a twisted state, it becomes very difficult to align the individual conductors when it is desired to terminate the conductors into correct position with a connector. More specifically, in terminating such cable typically the outer sheath is stripped off at a portion near the end and it then becomes necessary to flatten out the conductors into the original flat configuration prior to twisting and thereafter terminate it with an insulated displacement contact. As a result of the tendency to move back into its round configuration because of the prior twisting, this involves a long and tedious manual process whereby, for example, a single clip member is employed to hold the individual conductors in a flat configuration. Because of the tendency of the cable to move back into its twisted state prior to being clipped, this involves extensive positioning and repositioning the individual conductors until finally they are held in position and held with the clip for later termination with another tool containing a connector of the type having insulation displacement contacts, i.e., IDC connectors, as discussed above.
In accordance with the invention, these problems are obviated and a simple tool and system which permits both alignment and termination of such flat ribbon cable both of the round twisted type as well as conventional non-twisted flat ribbon cable is provided. In addition, the invention also resides in the method of terminating such types of cable.